Valve stem assemblies are commonly associated with wheels for heavy duty vehicles such as semi tractor/trailer and off-highway trucks and the like that have tubeless tire wheels. Without a tire installed on the wheel, a valve stem assembly is installed on a wheel so that one end is secured to the inner surface of the wheel, and the other end is accessible for connection with a source of pressurized air.
Valve stem assemblies are installed according to methods well known in the art. Typically, this involves inserting part of a valve stem assembly into a hole in the wheel and then threading a nut onto a threaded portion of the valve stem assembly on the outer surface of the wheel. Then, a tire may be installed onto the wheel and inflated by connecting the valve stem assembly to a source of pressurized air, as is well known in the art.
After a period of time, a valve stem assembly may become damaged and require repair or replacement. This is notoriously difficult, especially if the nut and threaded portion of the valve stem assembly have rusted or otherwise grown together. Removing such nuts from such threads using a wrench can be difficult, and becomes even more difficult if the edges on the nut become rounded off. Given the low cost of valve stem assemblies, practitioners have realized that is it often easier or more economical to simply break an old valve stem assembly off of a wheel.
To do so, practitioners have been know to use a variety of striking devices, but have found slide-hammer type devices particularly useful for removing valve stem assemblies. Slide-hammers are generally well known, and come in a variety of assortments depending on the relevant application. Slide-hammers generally include two portions that are concentrically arranged. One portion is held stationary against an object to be struck and the other portion is moved away from the stationary portion and brought back into contact with the stationary portion, thereby transferring the momentum of the moving portion to the stationary portion, and then to the object to be struck. Modifications on this basic idea have included specialized tips for contacting the item to be struck, with the tips having different shapes such as curved tips, punch tips, chisel tips, rounded tips, forked tips and the like. Slide-hammers have proven to be especially useful for working on wheels as they provide a lengthwise extension between the wheel, which is typically situated on the ground, and the practitioner, who is standing.
Another known modification to the basic slide-hammer design is where the contacting tip is not fixedly connected to the stationary portion, such tips being known in the art as floating tips. However, slide-hammers with floating tips often incorporate springs and other components and are assembled in a way that makes repair or disassembly extremely difficult. In one known tool, a floating tip assembly is threaded into the end of a slide-hammer, and the floating tip assembly comprises a floating tip and at least one spring held under compression. If the floating tip assembly is disassembled, it is very difficult to get its spring back under the appropriate compression and the floating tip assembly reassembled. Such a design is undesirable in at least two ways. First, it is not easy to manufacture or to remove or disassemble, thereby frustrating repair or replacement of the assembly's component pieces. Second, the arrangement of the floating tip assembly with the floating tip under a strong force from the spring substantially dampens the force transmitted to the object to be struck.
Thus, a need exists in the art for a punch tool that is easy to manufacture, easy to maintain, easy to operate and is effective in removing valve stem assemblies from wheels.